Evaluation and comparison of the performance of BDS-3 space-borne atomic clocks

At present, most of the space-borne atomic clocks used by the major global navigation satellite systems include rubidium atomic clocks, passive hydrogen master (PHM) clocks and cesium atomic clocks. The new independently developed space-borne rubidium atomic clocks and PHM clocks on BeiDou Global Navigation Satellite System (BDS-3) are important hardware improvements. In this paper, performances of new Beidou domestic atomic clocks are evaluated using precise clock offset data from September 2019 to September 2021 and compared with the mainstream space-borne atomic clocks of other satellite navigation systems. The results show that the BDS-3 space-borne PHM clocks have low drift rate and high stability at 86400s interval, which respectively reaches 8.26 × 10−16 and 5.13 × 10−15. These performances are only slightly lower than Galileo PHM clocks. The frequency stability at 86400s interval of BDS-3 rubidium clock is up to 9.03 × 10−15, which is 27.76% higher than GPS rubidium clocks.